The present invention relates to a laser machining apparatus capable of performing various machinings of workpiece efficiently by using any one or a combination of different laser beams.
FIG. 1 shows a construction of an example of a conventional laser machining apparatus which is disclosed in the joint research and development report in "composite Manufacturing System using Super High Performance Laser", Large Scale Project sponsored by Agency of Industrial Science and Technology of Japan. In FIG. 1, a reference numeral 1 depicts a CO.sub.2 laser ocsillator having an output power of 10 KW, 2 a console of the oscillator 1, 3 a 5 KW laser machining mechanism, which is provided with a pair of machining heads for welding and tempering, 4 a control device for the welding head, 5 a control device for the tempering head and 6 a 10 KW laser machining mechanism. Reference numerals 7 and 8 depict a control panel and a console of the laser machining mechanism 6. A reference numeral 9 depicts a laser machining managing device for managing whole of the laser machining apparatus, 10 a center post having a switch mechanism for switching the laser beam produced by the laser oscillator 1 between the laser machining mechanisms 3 and 6, and 11 an optical path control device responsive to a control signal from the laser machining managing device 9 for controlling the center post 10. Laser beam transmission paths are depicted by 3a and 6a.
In the conventional laser machining apparatus constructed as above, a laser beam derived from the CO.sub.2 laser oscillator 1 is branched at the center post 10 and transmitted through the optical paths 3a and 6a to the laser machining mechanisms 3 and 6 in a time sharing manner to realize time shared welding and tempering operations thereby, so that a workpiece can be welded and tempered successively. Therefore, when it is desired to perform other work than welding and tempering, such as, for example, cutting another machine which has a laser oscillator having an output power sufficient to cut the workpiece has to be prepared. An example of such a laser oscillator may be a TEM.sub.oo mode laser whose output power is as small as 1 KW and whose condensation performance is excellent.
In Japanese patent application Laid-Open No. 293694/1986, laser beams from a plurality of laser oscillators are delivered by controllable reflection mirrors to different machining tables so that time loss at respective tables is minimized. In this prior art, it is impossible to perform different machinings of a workpiece by using laser beams having different output powers and/or different wavelengths while the latter stays at a table.